Sure DoW intro is well made and looks cool and has da orks and gore and space marines etc. So, like, way cool. But other than that, I don't really understand why people love it THAT much. It doesn't really tell any deeper story. Sure it's short and compact introduction in to warhammer universe, but thats all.
The uncut Freelancer intro on the other hand is a completely different story. It also is a well made, and cool and stuff. The story it tells, has enough substance for another game. So it covers a lot of territory. It gives

to think. It is interesting.
But I-War intro is the greatest. It really is like a mini movie. It may not look as cool nowdays as some other intros. But but "camerawork", acting and script far surpass any intro I've seen. It tells what's the game about and introduces Jefferson Clay and what he's about. It really is something special.
Like the game itself.
Trailers and teasers I don't go into. IMO they can't be rated against eachother because there's ****load of them, and they usually are pretty awesome, often have interesting/clever/cool ideas/gimmicks.